This invention relates to apparatus for testing an optical circuit.
More particularly, the invention relates to a light source for testing an optical circuit. Light is used to test integrated optic devices.
An integrated optic chip (IOC) is made of an electro-optic material whose index of refraction increases or decreases depending on the direction of electric field applied to it. IOC's are analogous to integrated circuits (IC's) utilized in semiconductor technology. The signal processing in an IC is totally electric whereas in an IOC it is both optical and electrical. The term "integrated" in "integrated optic chip" implies that the chip has both electrical and optical parts. One or more external electrical signal(s) is applied to one or more electrodes formed on an IOC and the electrical signals change the index of refraction of one or more waveguides adjacent to the electrodes. Changing the index of refraction of a waveguide produces a concomitant change in the intensity and/or phase of light passing through the waveguide. An IOC device is a device which includes one or more IOCs.
During the testing of multiple IOC devices, it is common practice to provide a separate laser light source for each IOC device. This procedure is labor intensive, is costly, and can also make it difficult to readily determine when a particular laser is not operating properly.